The cash flow statement is one of the three core financial statements. It sorts every dollar into three buckets.
Most companies use the indirect method. Start with net income, add back non-cash charges like depreciation, then adjust for working capital. If receivables rise $1M, you booked $1M of sales you didn't collect, so CFO drops $1M. If payables rise $1M, you held onto supplier cash, so CFO rises $1M.
Healthy pattern: operating cash funds investment. A company that borrows every year to cover operating shortfalls depends on its lender to stay open.